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  1. #1
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    doubts

    1. Let's suppose I truncate a table and insert 1 million rows (it had 1 million rows before truncating). Do I need to rebuild indexes and analyze the table?

    2. How do I update a materialized view if it containts more than one table in from clause ?


    Thanks

    F.

  2. #2
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    Re: doubts

    Originally posted by Mnemonical
    1. Let's suppose I truncate a table and insert 1 million rows (it had 1 million rows before truncating). Do I need to rebuild indexes and analyze the table?


    Rebild Index is not required...Though Drop Index during bulk load and recreate them wud be good choice...

    Analyze - Might be (Not sure) if it really helps in improving performance.

    Originally posted by Mnemonical
    2. How do I update a materialized view if it containts more than one table in from clause ?
    RTM
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  3. #3
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    As far as I know, materialized views aren't updatable when you have more than one table in the definition...

  4. #4
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    I would definately analyze the table and indexes.

    index rebuild probably not required except for bitmap indexes.

    I don't understand what the problem is in refreshing a materialized view defined on multiple tables -- use dbms_mview.refresh (as i recall).
    David Aldridge,
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  5. #5
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    Re: doubts

    Originally posted by Mnemonical
    2. How do I update a materialized view if it containts more than one table in from clause ?
    Define Update. Update as in UPDATE sql statement or Update as in refresh?
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  6. #6
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    Define update: update a materialized view. I dont want to update the base tables, I want to update the mv, and it's formed by several tables (that's the why I dont want to use dbms_refresh), I use 'for update' clause and oracle does not allow it.

    So, whe I truncate a table and insert lots of rows using APPEND hint I need to analyze the table, ok, I'll do it. I'm going to truncate the table, insert /*+ append */ as select, then analyze table compute statistics.


    thanks.

    F.

  7. #7
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    analyze table compute statistics.
    you might look at dbms_stats.gather_table_stats as a better alternative.
    David Aldridge,
    "The Oracle Sponge"

    Senior Manager, Business Intelligence Development
    XM Satellite Radio
    Washington, DC

    Oracle ACE

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